Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!gem.mps.ohio-state.edu!usc!snorkelwacker!spdcc!dyer
From: dyer@spdcc.COM (Steve Dyer)
Newsgroups: comp.unix.aix
Subject: Re: IP routing subnet mask bug?
Keywords: routing subnet
Message-ID: <328@ursa-major.SPDCC.COM>
Date: 25 Oct 89 06:01:57 GMT
References: <464@janus.UUCP> <394@itcatl.UUCP> <468@janus.UUCP> <397@itcatl.UUCP>
Reply-To: dyer@ursa-major.spdcc.COM (Steve Dyer)
Distribution: usa
Organization: S.P. Dyer Computer Consulting, Cambridge MA
Lines: 25

In article <397@itcatl.UUCP> robin@itcatl.UUCP (Robin Cutshaw) writes:
>Guess I should have included more detail.  I am using ifconfig with
>netmask 255.0.0.0 and broadcast MYNET.255.255.255.  ifconfig shows
>the netmask to be ff000000 but it actually arp's 000000ff...

Uh, I don't know what you mean by "arp"ing 000000ff, but...  I'd ask:

What's your (Class A) net number for MYNET?  Strictly speaking, most systems
derived from the 4.x network code don't require you to specify a netmask if
your network convention is the same as the "natural" netmask for your network
number.

Urgh--that's awkwardly phrased.
Class A networks (001-127.h.h.h) have a "natural" netmask of 255.0.0.0.
Class B networks (128-191.n.h.h) have a "natural" netmask of 255.255.0.0, and
class C networks (192-223.n.n.h) have a "natural" netmask of 255.255.255.0.

I'm running with a class A net address (net 18) with a netmask of 255.255.0.0
(16 bits of host) with AIX PS/2, and it works flawlessly.  I suspect you're
neglecting to mention some bit of information here.

-- 
Steve Dyer
dyer@ursa-major.spdcc.com aka {ima,harvard,rayssd,linus,m2c}!spdcc!dyer
dyer@arktouros.mit.edu, dyer@hstbme.mit.edu